Wooden framing fabrication system

ABSTRACT

The fabrication system comprises a conveyor operable to advance a jig table carrying wooden frame members positioned thereon forming a truss, panel or the like to successively locate the longitudinally spaced butt joints thereof below a press platen for embedment of nailplates of the type having a plurality of teeth stuck therefrom into the butt joints. The conveyor and press are controlled via a circuit including an index wheel actuated switch which automatically and sequentially stops the conveyor when successive butt joints are located below the press, actuates the press to embed the nailplates, and restarts the conveyor to advance the jig table to locate successive butt joints below the press. The index wheel is driven from the conveyor and has a plurality of recesses spaced a predetermined distance one from the other about the periphery thereof representing a predetermined distance of conveyor advance. A plurality of magnetic pins are inserted in selected recesses of the wheel and project to successively actuate the switch controlling the conveyor and press. The selectivity of the spacing between adjacent pins permits fabrication of trusses, panels or the like of different sizes and types.

United States Patent [45] Patented Aug. 31, 1971 [73] Assignee AutomatedBuilding Components, Inc.

Miami, Flat.

[54] WOODEN FRAMING FABRICATION SYSTEM 10 Claims, 15 Drawing Figs.

[52] US. Cl 100/53, 100/222, 227/152 [5 1] Int. Cl 1330b 15/16 [50]Field ofSearch [56] References Cited UNITED STATES PATENTS 3,443,5135/1969 Jureit et al. 100/53 Primary Examiner-Billy J. WilhiteAIIorney-Le Blane & Shur ABSTRACT: The fabrication system comprises aconveyor operable to advance a jig table carrying wooden frame memberspositioned thereon forming a truss, panel or the like to successivelylocate the longitudinally spaced butt joints thereof below a pressplaten for embedment of nailplates of the type having a plurality ofteeth stuck therefrom into the butt joints. The conveyor and press arecontrolled via a circuit including an index wheel actuated switch whichautomatically and sequentially stops the conveyor when successive buttjoints are located below the press, actuates the press to embed thenailplates, and restarts the conveyor to advance the jig table to locatesuccessive butt joints below the press. The index wheel is driven fromthe conveyor and has a plurality of recesses spaced a predetermineddistance one from the other about the periphery thereof representing apredetermined distance of conveyor advance. A plurality of magnetic pinsare inserted in selected recesses of the wheel and project tosuccessively actuate the switch controlling the conveyor and press. Theselectivity of the spacing between adjacent pins permits fabrication oftrusses, panels or the like of different sizes and types,

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SHEET k UF 5 /3/' w 43/ Yo 7 a MTR /43 L00 w LOWER RAISE REV FWD PU n9/4/ WOODEN FRAMING FABRICATION SYSTEM This is a division of applicationSer. No. 676,943, filed Oct. 20, 1967, now U.S. Pat. No. 3,443,513.

BACKGROUND OF THE INVENTION The present invention relates to a systemfor fabricating wooden trusses, panels or the like and particularly to aconveyor, press and control apparatus therefor whereby nailplates aresuccessively embedded in the spaced butt joints of wooden frame membersforming the trusses, panels or the like.

The wooden building construction industry has recently made tremendousstrides forward with the advent of fabrication techniques wherein buttjoints of wooden frame members forming trusses, panels and the like arefastened together by embedding nailplates of the type having a pluralityof teeth struck therefrom into the joints, typical nailplates for thispurpose being described in US. Pat. No. 2,877,520. Previous methods ofapplying the nailplatesto the butt joints, such as hand nailing,employing individual power-operated presses at each joint, etc., havebeen not only time consuming, laborious and accordingly expensive, butdo not lend themselves to high production truss fabrication on anassembly line basis.

In conventional fabrication techniques which utilize poweroperated trusspresses, wooden frame members, consisting of elongated chords and crossmembers, are prepositioned in assembled relation on a jig table withconnector plates located at opposite sides of the truss, panel or thelike at the butt joints. Thereafter the connector plates are pressedinto the butt joints to fasten the frame members together and form thecompleted truss, panel or the like. A press capable of providing theforegoing action is disclosed in U.S. Pat. No. 3,079,607. While thistype of truss press is satisfactory, this press per se and othersemployed for like purposes are not particularly adapted for operation inconjunction with elongated trusses having widely spaced butt jointswherein the press head must be repeatedly raised and lowered and the jigtable carrying the truss manually manipulated to locate each of the buttjoints of the truss below the press head or platen for each pressoperation.

Other conventional fabricating techniques employ a plurality offluid-operated press heads, each mounted 'on bases movable inlongitudinal and transverse directions whereby the press heads areindividually located relative to each butt joint of a particular sizeand type of truss. The plural presses are then simultaneously actuatedto embed the several nailplates into the butt joints. The press headsthus employed, however, must be accurately and often laboriouslyrepositioned for different sizes and types of trusses, panels or thelike having different locations and spacings between the butt joints.Additionally, in most instances the press heads must be movedtransversely of the truss, panel or the like to permit the same to bewithdrawn from the press, thus necessitating repositioning of theseveral press heads for the completion of each truss, panel or the like,with the result of that rapid, efficient inexpensive fabrication oflarge numbers of even the same size and type of truss cannot berealized.

SUMMARY OF THE INVENTION The present invention provides a uniquefabrication system for automatically or manually forming completedtrusses, panels or the like, hereinafter referred to as trusses. Toaccomplish this, wooden frame members are prepositioned on a jig tableto form a truss and nailplates of the foregoing type are positioned'onopposite sides of the butt joints. The jig table is mounted on aconveyor for advancement through and between the heads or platens of apress which is indexed to successively embed the nailplates in the buttjoints as the jig table and frame members are successively advancedthrough the press. A control apparatus including an index wheel is pro-I vided to successively stop the jig table at predetermined positionsalong the conveyor in accordance with the predetermined successivelongitudinal spacing between the butt joints of the prepositioned framemembers to: successively locate the the butt joints and raisedtherefrom, and the conveyor is ad-" vanced, in response to sequentialactuation of the control circuit actuating index wheel which rotatespredetermined distances proportional to the successive longitudinaldistances between the spaced butt joints.

Additionally, the index wheel of the present invention can be readilyprogrammed to advance the conveyor and control the press to embed thenailplates in trusses of different sizes and types having variouslyspaced butt joints. The index wheel has a plurality of cylindricalrecesses spaced predetermined distances one from the other about theperiphery of the wheel corresponding to a predetermined advance of theconveyor. A plurality of pins are provided for releasable magneticengagement in selected recesses whereby the spacing between the pins isa whole multiple of the peripheral spacing between the recesses. Thewheel and pins are arranged to actuate a switch which cycles theconveyor stop, the press operation, and the conveyor advance, the pinsactuating the switch in accordance with the predetermined spacingbetween the butt joints.

The index wheel is driven from the conveyor whereby conveyor and wheelpositions are synchronized. Accordingly, the wheel position relative tothe actuating switch is proportional to the distance the conveyor hasadvanced, the initial wheel setting or arrangement of the pins on thewheel corresponding to the initial conveyor position. After completelyfabricating the truss and at the end of the conveyor advance whereuponthe completed truss is unloaded, the jig table actuates limit switchesto retract the jig table along the conveyor to its initial position andthus repositions the index wheel to its original position. Additionalframing members can then be assembled thereon for advancement throughthe press as before. In this manner, the press control system can be setfor a truss of a particular size and type and a plurality of liketrusses can be subsequently formed without readjusting the conveyor andpress setting.

To program the press control system for trusses of different sizes andtypes, the pins in the index ,wheel, being magnetically secured withinthe recesses, can be readily and easily withdrawn therefrom forreinsertion in other selected recesses to thereby vary the spacingbetween adjacent pins. Since the latter spacing is a function of theconveyor advance, the known longitudinal spacing between the butt jointsof different sizes and types of trusses can be set into the index wheelby correlating such known spacing between the butt joints and thespacing between adjacent pins.

Accordingly, it is an object of the present invention to provide afabrication system for successively embedding nailplates into the spacedbutt joints of wooden frame members forming a truss, panel or the like.

It is another object of the present invention to provide a fabricationsystem which is readily and easily adjusted to form trusses, panels orthe like of different types, sizes and shapes.

It is a further object of the present invention to provide a trussfabrication system which can be operated automatically or manually asdesired.

It is still another object of the present invention to provide a trussfabrication system which is simple in construction, rapid in operationand inexpensive to manufacture.

It is another object of the present invention to provide a trussfabrication system including a press, conveyor and control thereforwherein the press and conveyor can be indexed for a particular size andtype of truss and any number of identical trusses fabricated withoutresetting the press for each truss run.

It. is still a further object to provide a control-actuating index wheelwhich can be readily and easily adjusted to a plurality of selectedactuating positions.

It isstill a further object of the present invention to provide acontrol-actuating index wheel having a pluralityof predetermined spacedpositions therealong and a plurality of actuating elements easily andreadily secured in'selected locations in said spaced positions.

These and further objects and advantages of the invention will becomemore apparent upon reference to the following specification, claims andappended drawings.

BRIEF DESCRIPTION OF THE DRAWING FIGURES .ease of illustration;

FIG. 2 is an enlarged fragmentary plan view-thereof illustrating a jigtable carrying a truss on a conveyor in pressing position with only thelower press platen being shown;

FIG. 3 is a transverse sectional view thereof taken about on line 3-3 ofFIG. 2;

FIG. 4 is a side elevational view of the index wheel and cabinettherefor;

FIG. 5 is a transverse elevational view of the index wheel and itsconnection with the conveyor drive with portions thereof broken away forease of illustration;

FIG. 6 is a fragmentary side elevational view of the drive connectionbetween the index wheel and the conveyor drive taken about on line 6-6of FIG. 5;

FIG. 7 is an enlarged fragmentary view of the actuating switch and pinassembly on the index wheel taken about on line 7-7 ofFIG. 5;

FIG. 8 is a transverse cross-sectional view thereof taken about on line8-8 of FIG. 7; l

FIG. 9 is a fragmentary enlarged perspective view of the pin assembly onthe index wheel;

FIG. 10 is an enlarged fragmentary elevational view of a conveyorchain-tensioning device;

FIG. 1 1 is a plan view thereof;.

FIG. 12 is a transverse elevational view of another form of theconveyor;

FIG. 13 is a schematic illustration of a fluid-operated press;

FIG. 14 is an electrical hydraulic schematic diagram illustrating thefluid controls for the press and conveyor drive; and

,FIG. 15 is a schematic illustration of the electrical controls for thepress system of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, there isshown the fabrication system of the present invention comprisinggenerally aconveyor 10, a

press 12 located substantially medially between the ends of 23. Conveyor10 has a pair of upstanding legs 24 spaced longitudinally therealong,the lower ends of legs 24 being supported in footings 26 of the usualtype and the upper ends thereof supporting fou'r laterally spacedelongated parallel beams 28 as seen in FIG. 2. Beams 28 form a pair oftransversely spaced conveyor sections 30 having longitudinally spacedrollers 32 journaled at opposite ends in the associated beams 28. Anelongated central member 34 is located between conveyor sections 30between the innermost beams 28 thereof and provides a guideway receivingconveyor drive chain 36. A hydraulic motor 38 drives chain 36 aboutsuitable idler rollers 40 mounted on centrally disposed stanchions 39located beyond opposite ends of conveyor 10 and about rollers 44 ofchain-tensioning devices 42 mounted on stanchions 39. As

best seen in-FIGS. 10 and 11, tensioning devices 42 each comprise a pairof arms 46 pivotally mounted adjacent their upper ends to the upper endsof stanchions 39 and pivotally mountagainst pin 49 to bias arms 46 in adirection to tighten chain I and has a pair of depending lugs (notshown) which connect with opposite ends of chain 36-whereby jig table 52is driven along conveyor 10 by chain 36. Wooden framing members 54 areprepositioned-on jig table 52 to form a truss, the framing members 54being held in suitable positions on jig table 52 by a plurality ofclamps (not shown) which may be of the type illustrated in US. Pat. No.3,241,585. Nailplates 56 are provided at the butt joints of the truss onopposite sides thereof, and, as seen in FIG. 2, the plates 56 to theright of press 12 have been embedded in the butt joints while the plates56 to the left of press 12 remain to be embedded, the jig table 52 beingadvanced along conveyor 10 in the direction from left to I right.

Another form of conveyor 10, illustrated in FIG. 12 and which is widerthan the conveyor illustrated in FIGS. 1 and 2, may be employed herewithto accommodate trusses having larger widths requiring larger jig tables.This form of conveyor comprises a pair of transversely spaced legs 60supporting a plurality of transversely extending members 62 atlongitudinally spaced positions along the conveyor. The lower ends oflegs 60 are suitable secured in footings as in the previous form and atransverse member 64 joins the transversely spaced legs and provides asupport for an elongated beam 66 which supports chain 36 below theconveyor. In this instance, four longitudinally extending conveyorsections 68 are provided, each having a pair of elongated transverselyspaced beams 70 pivotally mounting a plurality of longitudinally spacedrollers 72 therebetween. A central support beam 74 is mounted on members62 to guide chain 36 along the top of the conveyor.

Referring now to FIGS. 4-9, the control system includes the index wheel20 which is driven in rotation by chain 36 and arranged to successivelyactuate a microswitch 76. As seen in FIG. 5, wheel 20 is mounted forrotation on a frame assembly, generally indicated 77, comprising a pairof longitudinally spaced upright stanchions 78 suitably mounted onfootings 26 as by angle brackets 80, stanchions 78 being locatedadjacent one side of conveyor 10 and suitably mounted cabinet 18. Frame77 includes a transversely extending base frame 80 suitably connected atits inner end to a pair of upright stanchions 82 which lie belowconveyor 10 adjacent the centerline thereof. Base frame 80 mounts a pairof bearings 84 and opposite end portions of shaft 86 are journaled inbearings 84. A drive coupling 87 connects the outer end of shaft 86 withthe inner end of an axially reduced shaft 88, the outer end of thelatter driving reduction gearing 89 secured to stanchions 78 withincabinet 18. A reduction gearing output shaft 90 is keyed to the hub 91of wheel 20. A drive sprocket wheel 92 is suitably keyed on the innerend of shaft 86 and 2 pair of idler sprocket wheels 93 are journaledadjacent the upper ends of stanchions 82. A pair of idler wheels 94 arejournaled on stanchions 82 below idler sprocket wheels 93 anda thirdidler wheel 96 is journaled in a cross frame 98 secured at opposite endsto stanchions 82, idler wheel 96 being located above the drive sprocketwheel 92. Chain 36 extends longitudinally in threading engagement withdrive and idler sprocket wheels 92 and 93. Respective idler wheels 96and 94 maintain chain 36 in driving engagement with sprocket wheel 92and in engagement with sprocket wheels 93. Ac-

ing roller 44 therebetween as by pin 47. A rod 48 is pivotally mountedto the lower end of stanchion 39 and extends through a pin 49 pivotallymounted between the lower ends of arms 46. A spring 50 is carried on theend of rod 48 and bears cordingly, when motor 38 drives chain 36 aboutrollers 40 and 44 in a clockwise direction as seen in FIG. 1 to advancejig table 52 along conveyor 10, index wheel 20 is simultaneously rotatedtherewith through drive sprocket wheel 92, shafts 86 and 88, andreduction gearing 89 for purposes as will presently become clear.

As seen in FIGS. 5, 7, and 8, a microswitch 76 is mounted on a bracket106 secured to the inner wall of cabinet 18, bracket 106 being mountedfor vertical adjustment within cabinet 18 by screws 108 and switch 76being mounted on bracket 106 for longitudinal adjustment by bolts 1 10whereby depending switch-actuating arm 112 is adjustably positionedrelative to wheel 20. Switch 76 is a one-way actuated microswitch whichenergizes a circuit to automatically advance jig table 52 along conveyor10, stop jig table 52, lower and raise press platen 14 to embednailplates 56, and restart the conveyor to further advance jig table 52as will be described hereinafter.

As seen in FIGS. 4, 7, 8, and 9, wheel 20 has a plurality of cylindricalrecesses 114 opening through the outer face and adjacent the peripherythereof, recesses 114 being spaced a predetermined distance one from theother. A plurality of pins 116 having cylindrical bases 118 are providedfor insertion and snug retention in selected recesses 114 for purposesto be described. Each pin 116 has an elongated shank portion 120 havinga threaded inner end (not shown) which threadedly engages within acomplementary recess in base 118 whereby shank portions 120 of pins 116project from the face of wheel 20. A jam nut 122 secures the connectionbetween pin 116 and base 118. The surface of shank portion 120 ispreferably serrated and engages against roller 124 on the end of arm 112 to actuate switch 76.

It is a significant feature of the present invention that pins 116 arereleasably secured in the selected recesses 114 in a manner whichprovides for the ready and rapid withdrawal of pins 116 therefrom andreinsertion of the same into other selected recesses. To this end, wheel20 is formed of a ferromagnetic material, preferably steel, and bases118 of pins 116 are permanent magnets, preferably formed of Alnico 5.Accordingly, to insert in or rearrange the pins on wheel 20 to providefor the actuation of switch 76 in a desired time sequence, pins 1 16 canbe readily and rapidly withdrawn from or inserted in selected recesses114 as the magnetic attraction between bases 118 thereof and wheel 20assures secure retention of the pins in the recesses as well as easywithdrawal of the pins therefrom. An opening 126 is provided through therear face of wheel 20 into each recess 114 to equalize the pressure onopposite sides of the pin, thereby facilitating the insertion andwithdrawal of each pin 116.

It is also a feature hereof that switch 76 is successively actuated inresponse to consecutive predetermined advances of jig table 52 alongconveyor distances equal to the distances between successive butt jointsto thereby locate each butt joint successively below press platen 14 forembedment of the associated nailplates. Switch 76 is successivelyactuated in accordance with the predetermined spacing between theperipherally next adjacent pins 116. The spacing between next adjacentrecesses 114 is proportional to a predetermined distance advanced by jigtable 52 on conveyor 10 through the index wheel drive mechanism andreduction gearing 89. In the preferred form, reduction gearing 89provides for a rotary advance of index wheel equal to the peripheraldistance between the centers of next adjacent recesses 114 for each onefoot of jig table travel on the conveyor 10. Accordingly, if pins areinserted in successive next adjacent recesses 114, switch 76 would besuccessively actuated for each one foot of advance of the jig tablealong conveyor 10. Similarly, locating pins 1 16 in every other recesswould provide for successive actuation of switch 76 for every two feetof jig table advance. In this manner, trusses of various sizes and typeshaving various spacing between their butt joints can be readilyfabricated by locating pins 116 in selected recesses spaced one from theother in accordance with the spacing between the butt joints, it beingunderstood that platens 14 and 16, in the preferred form, have a widthextending in the longitudinal direction of the conveyor at least equalto 1 foot.

As illustrated in FIGS. 13 and 14, an electrically controlled fluidcircuit is provided and arranged in controlling relation to conveyordrive motor 38 and to the fluid-actuated press 12. Press 12 isillustrated schematically by the dashed lines, the upper platen 14 beingmovable with respect to the fixed lower platen 16 by a pair offluid-operated pistons and cylinders 130 and 131, respectively.Cylinders 131 are fixed on opposite ends of movable platen 14 and a pairof fluid lines 132 and 133 (FIG. 14) alternately supply pressurizedfluid to opposite sides of cylinders 131 to reciprocate platen 14. Fluidfrom a reservoir 134 is pressurized by an electrically driven pump 135.Fluid from pump 135 flows to a four-way, three-position control valve136 via a conduit 137. Valve 136 is biased to the illustrated neutralposition by a pair of springs 138 whereat input conduit 137 communicatesdirectly with an intermediate conduit 139 connected to a like four-way,three-position control valve 140. Valve 140 is similarly biased to theillustrated neutral position whereat conduit 139 communicates with areturn conduit 141 emptying into reservoir 134.

A pair of solenoids 136L and 136R are arranged to shift valve 136 toalternately lower and raise press platen 14 and are actuated in a mannerto be described. Actuation of solenoid 136L shifts valve 136 to theright as seen in FIG. 14 to provide pressurized fluid via conduits 137,142, and 133 to the lower sides of cylinders 131 to lower platen 14 withpressure fluid exhausting from the upper sides of cylinders 131 throughconduits 132, 143, 139 and 141 to reservoir 134. Actuation of solenoid136R shifts valve 136 to the left to provide pressurized fluid viaconduits 137, 143, and 132 to the upper sides of cylinders 131 to raiseplaten 14 with pressure fluid exhausting from the lower sides ofcylinders 131 via conduits 133, 142, 139, and 141 to reservoir 132.

A pair of solenoids 140Rv and 140 F are arranged to shift valve 140 andare actuated in a manner to be described to alternately operate motor 38in the forward or reverse directions, thereby respectively advancing orretracting jig table 52 along conveyor 10. It will be noted withreference to the control circuit hereinafter described that valve 138 isalways in the neutral position when the conveyor is being eitheradvanced or retracted and that valve 140 is always in the neutralposition when press platen 14 is being lowered or raised. Actuation ofsolenoid 140F shifts valve 140 to the left as seen in FIG. 11 to providepressurized fluid via conduits 137, 139, and 144 to motor 38 to driveconveyor chain 36 forwardly with exhaust. fluid returning to reservoir132 via conduits 145 and 141. Actuation of solenoid 140Rv shifts valve140 to the right to provide pressurized fluid via conduits 137, 139 and145 to motor 38 to drive the conveyor chain 36 in the reverse directionto retract jig table 52 with exhaust fluid returning to reservoir 132via conduits 144 and 141.

The electrical circuit disclosed in FIG. 14 is arranged to sequentiallyshift valves 136 and 140 to advance jig table 52 along conveyor 10, stopjig table 52, lower and raise platen 14, and restart conveyor 10, torepeat the foregoing conveyor press cycle successively as the buttjoints are successively located below platen 14 and to retract jig table52 along conveyor 10 after the truss is completely fabricated andremoved therefrom. The control circuit is illustrated in a detachedcontact mode wherein the various relays, represented by circles, openand close associated contacts in a manner to b described, normally openand closed contacts being denoted by the vertical pairs of parallellines and the slashed pairs of vertical parallel lines respectively,with the contacts having letter suffixes corresponding to the lettersuffixes of their actuating relays. A power source S is provided acrossa pair of supply lines 146 and 148, supply line 146 including a suitablefuse 149 and an emergency conveyor-press stop pushbutton switch 150which, when depressed as illustrated, breaks whatever completed circuitis controlling the press or conveyor operation. To start the fabricatingsystem, fluid motor 135 is actuated by momentarily depressing a motorstart pushbutton 151 which completes a circuit through motor startercoil M via lead lines 146, 152, a normally closed motor stop pushbutton153 and lead line 148. Energization of coil M closes normally opencontact 154 which maintains the motor circuit energized for continuousoperation after motor start button 151 is released. Actuation of fluidpump 135 pressurizes the circuit as described hereinbefore whereby fluidis maintained available for subsequent operation of press cylinders 131and hydraulic motor 38.

A brake circuit is energized across lead lines 146 and 148 and comprisesa bridge rectifier having a potentiometer 162 across the output thereof.Potentiometer arm 164 is connected in series with contacts 166F and 168Rand capacitor 170 to actuate a brake B connected in parallel withcapacitor 170, brake B being suitably connected to the drive connectionbetween motor 38 and chain 36 to brake jig table 52 as the latter isadvanced or retracted along conveyor 10.

Frame members 54 are now prepositioned and clamped, by means not shown,on jig table 52 with nailplates 56 located on opposite sides of the buttjoints. To commence fabrication in the automatic mode of operation andto initially advance jig table 52 along conveyor 10, a pushbutton 172 ismomentarily depressed to energize a circuit via lead lines 146, 174 and148 which actuates the automatic mode relay 176A, which in turn closesnormally open contacts 178A, 179A, and 180A. Closing of contacts 178Aand 179A energizes a circuit via lead lines 146, 182, and 184, throughnormally closed contacts 186L and 188R, through a pair of normallyclosed limit switches 190 and lead lines 192 and 148 to actuate solenoid140F and a relay 194F. Actuation of relay 194F opens normally closedcontact 166F to deenergize the brake circuit, thereby releasing chain 36for forward travel along conveyor 10. Actuation of solenoid 140F shiftsvalve 140 to the left as seen in FIG. 14 to drive motor 38 and chain 36in the forward direction as hereinbefore described, thereby advancingjig. table 52 along conveyor 10 toward press 12. It will be noted thatclosing of contacts 178A energizes an automatic modeholding circuit vialeads 146, 182, and 196, through normally closed contact 198R and leadlines 174 and 148 to maintain relay 176A actuated on an automatic modeindicator light 200 lit on console 22 via a lead line 202 afterautomatic mode pushbutton 172 has been released.

Wheel is initially synchronized with the conveyor advance in a manner aswill presently become clear to actuate microswitch 76 when the first ofthe butt joints of a particular size and type of truss is located belowthe upper press platen 14, it being understood that subsequent switchactuating pins are located in selected recesses 1 14 as hereinbeforedescribed and behind the first pin location. Actuation of switch 76energizes a circuit via lead lines 146 and 182, closed contact 178A,lead lines 184, 204, 206, 208, 209, and 148, to actuate a pressloweringrelay 2l0L and a pneumatic timing relay 212. Actuation of relay 210Lopens normally closed contacts l86L, thereby deenergizing solenoid 140Fwhereby valve 140 is spring-returned to the illustrated neutral positionto interrupt the hydraulic circuit to motor 38. Opening contact 186Lalso deenergizes relay 194F whereby contacts 166F return to the normallyclosed position to actuate brake B to stop forward movement of jig table52 and prevent further forward coasting thereof. Actuation of relay 210Lcloses normally open contacts 2141. to energize a holding circuit vialead line 216, a normally closed press stop button 218, normally closedpress raise pushbutton switch 220, a normally pressure-actuated switch222, and lead lines 208, 206, 209, and 148 to maintain relays 210L and212? actuated as pins 116 advance slightly beyond the actuating positionof switch 76.

Actuation of relay 212P closes normally open switch 224 after a shorttime delay, normally open contacts 226L being closed in response toactuation of relay 2101.. Solenoid l36L is thus energized after a shorttime delay via a circuit comprising lead lines 148, 228, closed switchand contacts 224 and 226L respectively, and lead line 148. As seen inFIG. 14, valve 136 is thus shifted to the right to complete fluidcircuit from reservoir 134 to the lower sides of cylinders 131, therebylowering press platen 14 as described before.

At the bottom of the press stroke, interconnected pressureactuatedswitches 222 and 230 reverse momentarily to actuate a press raisingrelay 232R via a circuit comprising lead lines 146, switch 218, leadlines 216, 234, normally closed press lowering pushbutton switch 236, alimit switch 238 which is open only when press platen 14 is raised, leadline 240, pressure switch 230 which is closed at the end of the pressdownward stroke, and lead lines 242 and 148. Momentarily opening switch222 breaks the press-lowering holding circuit to deenergize relays 210Land 2121, thereby opening contact 226L and switch 224 to deenergizesolenoid 136L and opening contacts 186L and 2141,. Simultaneousactuation of relay 232R opens normally closed contact 188R to open thecircuit through the conveyor forwarding solenoid F and relay 1941 Relay232R also closes normally open contact 244R to energize a press raisingholding circuit via lead lines 146, 216, 234, 246, 242, and 148 tomaintain relay 232R energized after switch 230 opens at the beginning ofthe press upstroke. Relay 232R also closes normally open contacts 248Rto energize solenoid 136R via a circuit comprising lead lines 146, 250and 148. As seen in FIG. 14, valve 136 is shifted to the left and afluid circuit is completed from reservoir 134 to the upper sides ofcylinders 131 to raise press platen 14.

At the end of the upstroke of platen 14, the latter opens limit switch238 to deenergize the press-raising holding circuit and relay 232Rwhereby contacts 244R and 248R are returned to their normally openposition and contact 188R returned to its normally closed position.Opening contact 248R deenergizes solenoid 136R whereby valve 136 isbiased to its neutral position by springs 138 as illustrated in FIG. 11.The return of contact 188R to the normally closed position energizes theforegoing described circuit to the conveyor forwarding solenoid 140F andrelay 194F, whereby normally closed contact 166F is opened to deenergizebrake B. Valve 140 is again shifted to the left to pressurize motor 38to advance the jig table 52 along the conveyor.

It will be appreciated that the foregoing described cycle of operation,that is, conveyor advancing, stopping, press lower ing and raising, andconveyor advancing, is repeated as many times as the number of pins inwheel 20 which corresponds to the number of longitudinally spaced buttjoints in the truss. As hereinbefore described, the spacing of pins 116about index wheel 20 is proportional to the distance that the jig table52 advances on conveyor 10 such that switch 76 is successively actuatedto initiate the conveyor stopping, press lowering and raising, andconveyor restarting operations as the butt joints are successivelypositioned in press position below platen 14. For example, for a trusshaving three butt joints with the intermediate butt joints spaced 10feet behind the initial butt joint and the last butt joint spaced 9 feetbehind the intermediate joint, the pins 116 are arranged on the wheel 20such that the first pin is inserted in recess 114 which would actuateswitch 76 when the first butt joint is in position below platen 14. Thenext pin would be inserted in a selected recess 114 corresponding to aconveyor advance of 10 feet which would, in the preferred form, locatesuch next pin 10 recesses behind the first recess. The third pin wouldaccordingly be located in a recess corresponding to an additionalconveyor advance of 9 feet and would therefore be located in the recessnine recesses behind the intermediate pin. In this manner, trusses ofdif ferent types having different sizes and spacing between the buttjoints may be fabricated.

After the truss is completely formed, jig table 52 is continuouslyadvanced along conveyor 10 until it actuates a pair of normally closedlimit switches 190 located adjacent the end of conveyor 10. Openingswitches 190 deenergizes solenoid 140F and relay 194F to retain contact166F to its normally closed position thereby braking and stopping thejig table advance. The completed truss can then be removed from jigtable 52.

To reverse the jig table travel along conveyor 10 and retract the sameto the initial position, a jig drum switch 252 is closed by a pressoperator to energize a circuit via leads 146, 254, and 256, closed limitswitches 258 and lead line 142 to actuate conveyor reversing relay 260Rvand solenoid 140Rv. Relay 260Rv opens normally closed contact 168R torelease brake B and opens contact 198Rv to deenergize the automaticmodeholding relay 176A and solenoid 140Rv shifts valve 140 to complete afluid circuit from a reservoir 134 to drive motor 38 in the reversedirection. Motor 38 accordingly retracts jig table 52 along conveyor 10through press 12 in the reverse direction until it opens limit switches258 located at the forward loading end of the conveyor 10 to deenergizerelay 260Rv and Solenoid 140R whereby contact 168R is closed to energizebrake B and contact lQSRv is again closed. Jig table 52 is thusrepositioned at the loading end of the conveyor and index wheel issimultaneously rotated therewith in the opposite counterclockwisedirection as seen in FIG. 4 to its initial position for the start ofanother run fabricating a truss of similar size and type having similarspacing between the butt joints. in the automatic mode, only startpushbutton 172 and drum switch 252 need be manually operated.

The complete truss fabrication cycle can be operated manually. Moreover,the manual controls may be employed to locate the initial or first pinposition on wheel 20 in an initial test run and thereafter a largenumber of like trusses may be fabricated in the automatic mode ashereinbefore described. To cycle the conveyor and press manually, jigdrum switch 252 is closed to energize solenoid 140F and relay 194F via acircuit comprising lead lines 146, 254, 192, and 148. The jig table 52advances from the loading position as before with wheel 20 rotatingtherewith until the first butt joint is located below press platen 14,at which time the press operator opens jig drum switch 252 to deenergizesolenoid 140F and relay 194F. With wheel 20 thus located, the first pin116 is inserted in the recess 114 which locates the pin for actuation ofswitch 76. To lower the press platen, pushbutton 236 is depressed toenergize relays 210L and 212? via the circuits comprising lead lines146, 216, 206, 208, 209, and 148, valve 136 shifting as before to lowerplaten 14.

At the bottom of the downstroke, switches 222 and 230 momentarilyreverse to deenergize the relays 2101. and 212P and button 220 isdepressed to complete a circuit via lead lines 146, 216, 234, 264, 242,and 148, to energize relay 232R. Relay 232R operates to shift valve 136as before and limit switch 238 opens at the end of the upstroke ofplaten 14 to deenergize relay 232. Drum switch 252 is again manuallyclosed by the operator to complete the circuit through solenoid 140F andrelay 194 to further advance jig table 52 along conveyor 10 such thatthe next butt joint is located below press platen 14. The placing of pin116 in wheel 20 and manual operation of the press and conveyor cycle isrepeated for as many butt joints as there are in the truss whereby, atthe completion of the fabrication cycle, pins 116 are located inselected recesses 114 to automatically stop the conveyor and initiatethe press cycle for any number of the same type and size of trusses thatare to be fabricated in the automatic mode. Alternately, subsequent pinsmay be inserted in selected recesses behind the first pin in accordancewith the measured spacing of the butt joints behind the first butt jointinasmuch as the advance of the conveyor and wheel are synchronized forproportionate advancement in a predetermined ratio.

It will thus be appreciated that any number of like trusses, panels orthe like may be fabricated after the pins in the index wheel areinitially set to selected positions corresponding to the known distancesbetween the spaced butt joints.

It is also significant that the press control system can be readily,easily and rapidly set up to accommodate trusses, panels or the likehaving different spacing between the butt joints therefore whereby highproduction rates can be attained, not only for like trusses, panels orthe like, but also for a wide range of size, type of configuration ofdifferent trusses, panels or the like.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof, The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of theclaims are therefore intended to be embraced therein.

What is claimed and desired to be secured by U.S. Letters patent is:

l. A fabrication system for successively embedding connector plates inthe spaced butt joints of prepositioned wooden framing members formingtrusses or the like comprising means for supporting the wooden framemembers, a press adjacent said support means for embedding the connectorplates into the butt joints of the members, means for mounting saidsupport means and said press for relative movement with said pressdefining a press position at each juxtaposition of said press and thebutt joints of the members carried by said support means, meansproviding for relative movement between said support means and saidpress to locate successive butt joints of the wooden members insuccessive press positions for embedment of the connector plates intothe wooden members at the butt joints thereof, and means arranged incontrolling relation to said moving means including index means operablein response to relative movement of said support means and said presssuccessive distances equal to the distances between consecutive buttjoints to successively actuate said press and embed the connector platesinto the wooden members at the butt joints thereof.

2. A fabrication system according to claim 1 wherein said control meansincludes switch means and said index means includes means carrying aplurality of spaced switch-actuating elements, the spacing betweenadjacent actuating elements being proportional to the predeterminedspacing between the butt joints, and means providing for relativemovement between said switch means and said carrying means forsuccessive actuation of said switch means.

3. A fabrication system according to claim 2 wherein said carrying meansincludes a plurality of mounting positions for said elements, meansreleasably retaining said elements in said mounting positions, saidelements being movable between mounting positions to selectively varythe spacing between adjacent elements.

4. A fabrication system according to claim 3 wherein adjacent mountingpositions are spaced a predetermined distance on said carrying meansproportional to a predetermined distance of relative movement betweensaid press and said support means, the spacing between adjacent elementsbeing a whole multiple of the spacing between the associated positions.

5. A fabrication system according to claim 1 wherein said control meansincludes switch means and said index means includes a rotatable wheel,said wheel mounting a plurality of spaced-actuating pins about theperiphery thereof, the spacing of successive adjacent pins one from theother being proportional to the successive predetermined spacing betweenthe joints, and means drivingly connecting said wheel to said movingmeans for rotating said wheel to successively actuate said switch.

6. A fabrication system according to claim 5 wherein said wheel has aplurality of spaced recesses opening through a sideface and adjacent theperiphery thereof for receiving said pins, and magnetic means forreleasably retaining said pins it said recesses, said pins being movablebetween the recesses to selectively vary the spacing between adjacentpins.

7. A fabrication system according to claim 1 wherein said index means isarranged in controlling relation to said moving means to successivelystop the relative movement between said press and said support means.

8. A fabrication system according to claim 7 wherein said moving meansincludes fluid motor means and a fluid circuit therefor having valvemeans controlling said fluid motor means, said index means includingswitch means arranged in controlling relation to said valve means toshift the latter and stop said fluid motor means.

9. A fabrication system according to claim 1 wherein said press includesa press platen and at least one fluid-actuated cylinder operable to movesaid platen toward and away from the joints, said control meansincluding a fluid control circuit having electrically actuated valvemeans operably connected with said cylinder, an electrical circuitarranged in controlling relation to said valve means, and switch meansin said electrical circuit, said indexing means being operable toactuate said switch means to energize said electrical circuit and shiftsaid valve to move the press platen toward and away from the joint.

tion to said valves, and switch means in said electrical circuit, saidindexing means being operable to actuate said switch means to energizesaid electrical circuit to shift said valves to stop the relativemovement of said press and said support means and move the press platentoward and away from the oint.

1. A fabrication system for successively embedding Connector plates inthe spaced butt joints of prepositioned wooden framing members formingtrusses or the like comprising means for supporting the wooden framemembers, a press adjacent said support means for embedding the connectorplates into the butt joints of the members, means for mounting saidsupport means and said press for relative movement with said pressdefining a press position at each juxtaposition of said press and thebutt joints of the members carried by said support means, meansproviding for relative movement between said support means and saidpress to locate successive butt joints of the wooden members insuccessive press positions for embedment of the connector plates intothe wooden members at the butt joints thereof, and means arranged incontrolling relation to said moving means including index means operablein response to relative movement of said support means and said presssuccessive distances equal to the distances between consecutive buttjoints to successively actuate said press and embed the connector platesinto the wooden members at the butt joints thereof.
 2. A fabricationsystem according to claim 1 wherein said control means includes switchmeans and said index means includes means carrying a plurality of spacedswitch-actuating elements, the spacing between adjacent actuatingelements being proportional to the predetermined spacing between thebutt joints, and means providing for relative movement between saidswitch means and said carrying means for successive actuation of saidswitch means.
 3. A fabrication system according to claim 2 wherein saidcarrying means includes a plurality of mounting positions for saidelements, means releasably retaining said elements in said mountingpositions, said elements being movable between mounting positions toselectively vary the spacing between adjacent elements.
 4. A fabricationsystem according to claim 3 wherein adjacent mounting positions arespaced a predetermined distance on said carrying means proportional to apredetermined distance of relative movement between said press and saidsupport means, the spacing between adjacent elements being a wholemultiple of the spacing between the associated positions.
 5. Afabrication system according to claim 1 wherein said control meansincludes switch means and said index means includes a rotatable wheel,said wheel mounting a plurality of spaced-actuating pins about theperiphery thereof, the spacing of successive adjacent pins one from theother being proportional to the successive predetermined spacing betweenthe joints, and means drivingly connecting said wheel to said movingmeans for rotating said wheel to successively actuate said switch.
 6. Afabrication system according to claim 5 wherein said wheel has aplurality of spaced recesses opening through a sideface and adjacent theperiphery thereof for receiving said pins, and magnetic means forreleasably retaining said pins in said recesses, said pins being movablebetween the recesses to selectively vary the spacing between adjacentpins.
 7. A fabrication system according to claim 1 wherein said indexmeans is arranged in controlling relation to said moving means tosuccessively stop the relative movement between said press and saidsupport means.
 8. A fabrication system according to claim 7 wherein saidmoving means includes fluid motor means and a fluid circuit thereforhaving valve means controlling said fluid motor means, said index meansincluding switch means arranged in controlling relation to said valvemeans to shift the latter and stop said fluid motor means.
 9. Afabrication system according to claim 1 wherein said press includes apress platen and at least one fluid-actuated cylinder operable to movesaid platen toward and away from the joints, said control meansincluding a fluid control circuit having electrically actuated valvemeans operably connected with said cylinder, an electrical circuitarranged in controlling relation to said valve meanS, and switch meansin said electrical circuit, said indexing means being operable toactuate said switch means to energize said electrical circuit and shiftsaid valve to move the press platen toward and away from the joint. 10.A fabrication system according to claim 7 wherein said moving meansincludes a fluid motor and said press includes a press platen and atleast one fluid actuated cylinder operable to move said platen towardand away from the joints, said control means including a fluid controlcircuit having electrically actuated valves operably connected with saidfluid motor and said cylinder, an electrical circuit arranged incontrolling relation to said valves, and switch means in said electricalcircuit, said indexing means being operable to actuate said switch meansto energize said electrical circuit to shift said valves to stop therelative movement of said press and said support means and move thepress platen toward and away from the joint.